They Limit Their Caffeine Intake
Drinking caffeine triggers the release of adrenaline. Adrenaline is the source of the “fight-or-flight” response, a survival mechanism that forces you to stand up and fight or run for the hills when faced with a threat. The fight-or-flight mechanism sidesteps rational thinking in favor of a faster response. This is great when a bear is chasing you, but not so great when you’re responding to a curt email. When caffeine puts your brain and body into this hyperaroused state of stress, your emotions overrun your behavior. The stress that caffeine creates is far from intermittent, as its long half-life ensures that it takes its sweet time working its way out of your body.
They Sleep
I’ve beaten this one to death over the years and can’t say enough about the importance of sleep to increasing your emotional intelligence and managing your stress levels. When you sleep, your brain literally recharges, shuffling through the day’s memories and storing or discarding them (which causes dreams), so that you wake up alert and clear-headed. Your self-control, attention, and memory are all reduced when you don’t get enough—or the right kind—of sleep. Sleep deprivation raises stress hormone levels on its own, even without a stressor present. Stressful projects often make you feel as if you have no time to sleep, but taking the time to get a decent night’s sleep is often the one thing keeping you from getting things under control.
via How Successful People Stay Calm – Forbes.